MARY LOUISE KELLY, HOST:
The coronavirus is mutating. We know that worrisome new strains are popping up around the world. We know these variants could reduce the effectiveness of vaccines in preventing COVID-19, so manufacturers may need to update those vaccines. But how will companies prove to the Food and Drug Administration that these changes are safe and effective? NPR pharmaceuticals correspondent Sydney Lupkin says the agency is working on a plan.
SYDNEY LUPKIN, BYLINE: Hey, Mary Louise.
KELLY: First, just catch us up on how widespread these variants are in the U.S.
LUPKIN: So there are now nearly a thousand confirmed cases of variant strains of COVID-19. And that's considered an understatement. Most of the variant strains are those first identified in the United Kingdom, but there are others seen originally in Brazil and South Africa that are causing some concern. Some of the mutations allow the virus to more easily infect people, and some make it harder for immune systems to fight the virus off. So the fear is that the vaccines that the United States has spent billions of dollars researching, developing and purchasing will be rendered less effective.
KELLY: And how will we know? Will it be immediately obvious if the vaccines are just not working well enough against the variants?
LUPKIN: Well, it's definitely not time to panic yet. Dr. Anthony Fauci said during a White House briefing this week that the Moderna and Pfizer vaccines seem to be effective against the variant identified in the U.K. That's the variant expected to become the dominant strain in the U.S. by the end of March. So he says to keep following public health guidelines and getting vaccinated. As far as when it's time to change the vaccines, here's Dr. Paul Offit, who serves as an adviser to the FDA.
PAUL OFFIT: You know that a line is crossed if you see people who are fully immunized with these vaccines - let's say the mRNA vaccines - that nonetheless, when infected with a variant, are being hospitalized. That's when the line gets crossed. And to date, that has not happened.
LUPKIN: Still, everyone should prepare, he says. And the FDA is doing that.
KELLY: And how is the FDA preparing? How would they go about evaluating an altered vaccine? Or I suppose maybe we're talking an altered booster shot?
LUPKIN: A lot is up in the air, but FDA officials have said they're working on a playbook, and they'll publish guidance documents for industry in the coming weeks. What we do know is that the agency is aiming to be nimble, which likely means officials will look for studies of a few hundred people rather than the tens of thousands required the first time around. Acting FDA commissioner Dr. Janet Woodcock says a lot will depend on how fast variant strains crop up and how the existing vaccines stand up to them.
JANET WOODCOCK: So the situation is very fluid. But we think there are things short of doing full-fledged (unintelligible) trials that we can use to shift or perhaps add components to existing vaccine.
LUPKIN: She says the agency will likely also convene its advisory committee before making a decision on an updated vaccine.
KELLY: And how long might that take?
LUPKIN: Probably a few months. Of course, this pandemic is unprecedented in so many ways. But we can look to historical examples for clues. Genevieve Kanter, a health economist at the University of Pennsylvania, says the best analogy is the H1N1 pandemic in 2009. That year, the FDA learned about the seriousness of H1N1 after it had already approved the seasonal flu vaccine. It convened an advisory committee in late July.
GENEVIEVE KANTER: By September, mid-September, four supplements had been approved against H1N1. So they can do it, you know, certainly under two months.
LUPKIN: It's worth noting that it takes the agency time to carefully review reams of data and documents. The public usually first hears about trial results from company press releases. But the FDA needs to make sure that the underlying data are solid, that the company can make the vaccine according to its own recipe and that the shots stay stable when they're stored and transported.
KELLY: So many moving parts. That's NPR's Sydney Lupkin.
LUPKIN: You bet.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.